Low boost

[22EcoDs]

To give my statement above as much validity as Jscan provides me, here are some screen shots this morning on the way through Denver to show some data around boost range. I pulled up a few metrics as I was looking for some other indicators related to my intake, I provided both the computer boost requested and actual as measured by the engine. It does hit 40PSi on hard pulls. Also at the top is throttle position as reference to how much boost the turbo creates at various positions. what I was looking for this morning was Mass air flow request to actual to help confirm why im getting P200a/b codes... plugged up intake for sure. Has a brand new air filter install 3600 miles ago so likely not contributing..
Anyway, here's some data points as promised:

And also, Jscan is Awesome!! Thank you Piotr Bialic for an awesome tool for us to use. Sure as hell can't get this kind of data from Jeep

There's no way your EGT is that low at that boost pressure.

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[Rusty PW]

There's no way your EGT is that low at that boost pressure.

At 30 psi. I'm looking at 1,100F+ turbo inlet temp.

 

[Sbro2021]

There's no way your EGT is that low at that boost pressure.

Well aware captain. I took that snapshot from a nominal driving condition and punched it for the 5 seconds it took to get the screen shot at high boost and got back off just to show that my rig does get there by the means with which I have to measure it. That can be done without 1300 deg boost temps. They don’t climb that fast by measurement of thermocouple. I see 1300+ every time when I pull my trailer or any sustained pulls if I’m not careful. I have plenty of shots of egt pulling my trailer over loveland and vail pass here in CO because those are metrics I watch when pulling. As I have said, I’m relying on the tools I have to take care of my truck and am at the mercy of its accuracy. Hers a pic I took when I was trying to collect data to show jeep about the cooling issues this engine setup has in the glad. There is a 1200+ just to get a shot in time of what it was doing.

 

[22EcoDs]

At 30 psi. I'm looking at 1,100F+ turbo inlet temp.

Easily. I hit 1300 on my ScanGauge at full throttle pulls.

 

[Vtur]

Mine boost topped out at 26.5 psi on a Scangauge 2.

 

[bb121]

To give my statement above as much validity as Jscan provides me, here are some screen shots this morning on the way through Denver to show some data around boost range. I pulled up a few metrics as I was looking for some other indicators related to my intake, I provided both the computer boost requested and actual as measured by the engine. It does hit 40PSi on hard pulls. Also at the top is throttle position as reference to how much boost the turbo creates at various positions. what I was looking for this morning was Mass air flow request to actual to help confirm why im getting P200a/b codes... plugged up intake for sure. Has a brand new air filter install 3600 miles ago so likely not contributing..
Anyway, here's some data points as promised:

And also, Jscan is Awesome!! Thank you Piotr Bialic for an awesome tool for us to use. Sure as hell can't get this kind of data from Jeep

Any concern with the air flow measured vs target being so far off? I’m troubleshooting a different issue and noticed mine does the same. They will stay relatively close to each other until I get on the highway and then my target air flow jumps 2-3x

 

[Sbro2021]

I haven't dug into where and how that is measured if it is strictly the MASS sensor or a combination of metrics from other devices on the engine too. I have yet to see MASS actual/target match up. Maybe from the intake restriction to include the filter, box piping, turbo, turbo piping, Which I believe is reduced on purpose to create more pressure post turbo on the clean side..(turbo fanatics please chime in here) Intercoooooler, more piping, EGR, all add up to variance and restriction from perfect conditions. The computer may just want perfection and forgot it was managing an Italian soot machine wrapped in jeep engineering imperfection in a truck that clearly wasn't engineered to fit that motor into and live in a healthy, cool state. I haven't had any issues since the intake replacement other than a glow plug here of there since.

 

[LZY HIKR]

So yesterday I was driving a long distance on a slow highway with some traffic (50-60mph) and started noticing the truck was having trouble on cruise control...not accelerating in gear and resorting to downshifting. I used the Tazer's functions to bring up boost and I was only getting 1-3 psi while in easy cruise, and no better with no power or throttle response until it kicked down to 5th or so, got above 2500rpm, then would produce about 24 psi boost and rocket forward. Upshift and boost fell to low values again. RInse and repeat ad naseum until I got to my destination.

After being parked for an hour I started it back up and continued onwards. Drove completely normal from then onwards making 8~ish psi cruising in 8th and building boost with throttle while in gear, no longer requiring big downshifts to build boost. No CELs or on-dash errors occurred the entire time and operating temps were normal.

I read somewhere an active regen can mess with boost, is that the case?
What else should I be looking at or investigating? The turbo still spooled eventually and since it returned to normal after a system reset that makes me think nothing is wrong mechanically and something electronic was off. Variable vane actuator or something?

Have you fixed this problem? Mine has started doing the same thing with a GDE tune.
Pull it over and shut it off, then start it up again and it seems to reset. Also notice that when it does this on occasion the glow plug warning light will come on and it won't start. Cycle the starter button and everything seems to reset.

 

[Sting-Gray Neutral Pres.]

I can’t confirm it was the cause, but a few months later my low pressure EGR cooler failed when that was happening the ECU cut boost in a similar but more dramatic way. But it had thrown a CEL by that point. I suspect that episode was an early sign.

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